Device for treating and/or handling articles

ABSTRACT

A device for treating and/or handling articles ( 10 ), especially molds in the production of chocolate articles, comprises a gripper ( 6 ) that is arranged on arms ( 3.1 - 3.5 ) which can be displaced along a rail ( 1 ) on carriages ( 2.1 - 2.4 ). At least three arms ( 3.1  to  3.4 ) are connected to the gripper ( 6 ), every arm having its own joint ( 6, 7, 29 ) on the gripper ( 6 ) which joint is independent of the other arm.

BACKGROUND OF THE INVENTION

The present invention relates to a device for treating and/or handlingobjects, in particular of molds for the production of chocolatearticles, by means of a gripper which is arranged on at least three armswhich can each be moved along at least one rail on two outer carriagesand one inner carriage, with an outer arm on the outer carriage crossingan inner arm on the inner carriage.

Devices of the abovementioned type are known and are commerciallyavailable in many forms and embodiments. In general, they are referredto as robots and are used to move objects of any type from one point toanother desired point during automated operation. Just by way ofexample, reference is made to DE 299 20 995 U1, which discloses a devicefor manipulation of printed circuit boards. In this case, a handlingdevice with suction elements on a plate is located in a base housing,with the handling device taking printed circuit boards out of a cassettewith an inclined positioning wall, or unstacking them in a correspondingcassette. The handling device has a hydraulic cylinder from which apiston rod can be extended, on which the plate with the suction elementsis arranged. This cylinder rotates about an axis, and the picking up andinsertion activity is achieved by extension of the piston rod.

In a similar manner, DE 296 22 288 U1 also discloses where printedcircuit boards and adhesive layers (prepregs) are joined together in adevice. This is done by appropriate suction plates on carriages whichare guided on rails.

U.S. Pat. No. 6,557,235 B1 describes a linear robot which is used fortreatment or handling tasks. The device comprises a machine frame, amobile platform and two linear guides. A mobile platform is connectedvia the connecting elements to the linear guides, with two connectingelements being connected to the platform by means of the same joint.Grippers or tools can be attached to the mobile platform.

Furthermore, WO 99/08832 A1 discloses a device for movement andpositioning of an object on a plane. In one exemplary embodiment, theobject is connected to a respective carriage via three arms. In thiscase, the arms of two adjacent carriages form a common joint, or each inits own right forms an adjacent joint, on the object. In a furtherexemplary embodiment of the invention, an inner arm then crosses anouter arm, with the two outer arms forming a common joint on the tool.

WO 99/32256 A1 discloses a similar subject matter as well, although inthis case an outer arm crosses the inner arm.

The present invention relates in particular to the movement of objectsin the foodstuffs field, and in this case in the production ofconfectionery articles, such as chocolates or the like. Theseconfectionery articles are normally produced in a multiple mold, whichis then moved to a further treatment station for hardening. Until now,this has been done by means of commercially available robots whichoperate using hydraulics or pneumatics. In particular, these are subjectto hygienic reservations. Furthermore, the speed of such hydraulicrobots leaves much to be desired, and the accuracy with which, forexample, multiple molds have to be associated with the correspondingoutput nozzles can be achieved only with difficulty by means ofhydraulic or pneumatic robots.

The object of the present invention is to develop a low-cost device ofthe abovementioned type which can be produced easily and operatesextremely precisely.

SUMMARY OF THE INVENTION

In order to achieve the object, an outer arm which crosses an inner armforms a common joint with a further outer arm on the gripper, or elsecrosses the further outer arm and forms its own joint with the gripperbeyond the joint.

This arrangement provides the guidance for the gripper with considerablerobustness, thus considerably improving the guidance precision.Furthermore, this makes it possible for the gripper not only to beraised or lowered, but also to be pivoted. The gripper can therefore beused in a highly versatile manner.

In the case of both the first and the second exemplary embodiment, itmay be considered to be advisable for two arms to form a parallelogram,that is to say to be arranged on the same side offset with respect tothe gripper. The third arm, on the other side of the gripper, crossesthe parallelogram or at least one arm of it. This keeps the width of theoverall device as small as possible.

In another exemplary embodiment of the invention, in contrast, the armsdo not form a parallelogram but can be moved as required on one or morerails. This allows the gripper to carry out any desired movement about ajoint, for example even a 360° rotation.

In another exemplary embodiment, two arms are made shorter, with oneshorter arm section belonging to a parallelogram with a longer arm. Attheir free end, the two short arm sections are connected to a centerjoint, to which two fixing arm strips, which are connected to thegripper, are also connected. An articulated arm arrangement such as thisalso allows specific movements of the gripper to be carried out.

The exemplary embodiments which have just been mentioned can bedeveloped as required. Further exemplary embodiments are within thescope of the invention.

Furthermore, it is also feasible that an attachment with a transfersurface, which is positioned obliquely with respect to the grippersurface, is located on the gripper, and this likewise makes it possibleto take account of special requirements for gripper movement.

In order to allow a three-dimensional movement of the gripper in spaceas well, a further rail may also be associated with the abovementionedrail, wherein, preferably, a linear drive is likewise located betweenthe first rail and the second rail. The second rail should run obliquelywith respect to the first rail, or even at right angles to it.

The invention also provides for a linear drive to be arranged betweenthe carriages and the rail.

The expression a linear drive or linear motor means an electrical drivemachine. In contrast to the widely used rotating machines, a linearmotor does not move the objects connected to it in the form of a rotarymovement, but in a linear movement (translation movement). Onepossibility for designing a linear motor is to develop a rotatingstepping motor onto a plane. For example, DE 10 2005 047 819 A1describes a linear motor such as this, to which reference is made, as aresult of which the linear motor will not be described any further here.

For the present situation, this means that the linear drive is arrangedbetween the rail and the carriage. For example, correspondingpermanent-magnet strips can be arranged as part of a stator on the rail,with these permanent-magnet strips having alternate polarity. Themovable part of the linear motor is separated therefrom by an air gap,with this movable part having the corresponding windings which can beenergized in order to operate the linear drive. This arrangement may, ofcourse, also be reversed.

Linear motors have considerable advantages. On the one hand, theyoperate without any gearboxes, thus considerably assisting theirhandling and their use. They operate without wear, as a result of whichthey can also be used in particular in clean rooms. A further advantageis that they can be subjected to an extraordinarily high accelerationand nevertheless maintain a predetermined position or a position thathas been moved to, extremely precisely.

Particularly because of the enormous acceleration, which, of course,allows processes to be speeded up considerably, the further transportmembers which are connected to the carriage must be designed such thatthe objects to be moved, whose weight increases very greatly, inrelative terms, during the enormous acceleration, can also be held. Forthis purpose, provision is made for a further arm to be connected to thegripper, which arm can be moved along a rail on a further carriage.Although protection is also sought for this feature and the followingfeatures independently of the linear motor, the essence of the inventionis desirable in particular for use of a linear motor or of two linearmotors with two carriages. In this way, the gripper is not onlysuspended on one arm, and would in this case be subject to pendularmovements, but it is supported on a second arm, with the two arms andthe rail preferably being arranged in a triangular shape with respect toone another. In this case, only the arms need be designed appropriatelyto withstand compression and tension.

In one preferred exemplary embodiment of the invention, a force storecan be arranged between the gripper and carriage. This may be acorresponding hydraulic, pneumatic, electrical or mechanical device, forexample a helical spring. This force store is particularly necessarywhen a linear motor as described above is used. If the electrical powerfor the machine fails, then there is a risk of the gripper droppingdownwards. This is prevented by the force store, as a result of whichthis force store forms an emergency stop.

The present invention can be used for many purposes as a robot or fortreatment of workpieces. It is primarily intended to be used for theproduction of chocolate articles. In this case, the device is used notonly to move, for example, molds, in which chocolate articles areformed, as is described by way of example in EP 0 981 280 A1. In orderto move the corresponding mold, the device according to the invention isgenerally arranged on a ceiling, and works vertically.

However, the device could also, for example, be used to transport themold further, in a similar manner to DE 298 20 564 U, or else forstripping excess chocolate mass from the mold. In this case, appropriatetools are provided on the gripper. For example, this may be a scrapingtool which is lowered by means of the gripper obliquely from above ontothe mold and, after the individual mold receptacles have been filled andhave cooled down, can strip off the chocolate mass projecting above themold receptacles. Appropriate sensors then govern the speed and pressureof this process, and the linear drive as mentioned above is once againparticularly suitable for this purpose.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features and details of the invention will becomeevident from the following description of preferred exemplaryembodiments and from the drawing, in which:

FIGS. 1 a to 1 f show side views of one exemplary embodiment of a deviceaccording to the invention for moving objects in different in-usepositions;

FIGS. 2 a to 2 f show side views of a further exemplary embodiment of adevice according to the invention for moving objects in different in-usepositions;

FIGS. 3 a to 3 f show side views of a further exemplary embodiment of adevice according to the invention for moving objects in different in-usepositions;

FIGS. 4 a to 4 f show side views of a further exemplary embodiment of adevice according to the invention for moving objects in different in-usepositions;

FIGS. 5 to 7 show side views of further exemplary embodiments of adevice according to the invention for moving objects;

FIG. 8 shows a perspective view of a device according to the inventionfor handling objects;

FIG. 9 shows a front view of a further exemplary embodiment of a deviceaccording to the invention for moving objects.

DETAILED DESCRIPTION

According to FIGS. 1 a to 1 f, three carriages 2.1 to 2.3 are arrangedon a rail 1 and can be moved along this rail 1. An arm 3.1 to 3.3 isconnected via a joint 4.1 to 4.3 to each carriage 2.1 to 2.3. At itsfree end, the arm 3.2 is connected via a further joint 5 to a gripper 6,while the two other arms 3.1 and 3.3 have a common joint 7 on thegripper 6. Gripping members 9, for example suction cups, are located ona gripper surface 8 and can hold an object 10 that is to be moved. Thisobject 10 is located in a container 11 and is intended to be moved ontoa supporting surface 12, for example a conveyor belt.

The method of operation of the present invention is as follows:

As shown in FIG. 1 a, the gripper 6 is arranged above the container 11by means of an appropriate movement of the carriages 2.1 to 2.3. Inorder to lower the gripper 6 exactly vertically onto the object 10 asshown in FIG. 1 b, all three carriages 2.1 to 2.3 are moved through thesame distance, with the carriages 2.2 and 2.3 following and both runningto the carriage 2.1. In order to raise the object 10 exactly verticallyout of the container 11, the three carriages 2.1 to 2.3 are once againmoved back through the same distance as a result of which, as shown inFIG. 1, they are in the initial position as shown in FIG. 1 a.

The three carriages 2.1 to 2.3 are now moved through the same distanceto the right, as shown in FIG. 1 d, until the object 10 is located abovethe supporting surface 12. All three carriages 2.1 to 2.3 are then onceagain moved through the same distance, to be precise the carriages 2.2and 2.3 successively and the carriage 2.1 towards the carriages 2.2 and2.3. This results in the gripper 6, together with the object 10, beinglowered onto the supporting surface 12.

The gripping members 9 are now released and, as shown in FIG. 1 f, thecarriages 2.1 to 2.3 are moved back to the initial position as shown inFIG. 1 d, with the object 10 remaining on the supporting surface 12.

The exemplary embodiment of a device according to the invention formoving objects as shown in FIGS. 2 a to 2 f differs from that shown inFIGS. 1 a to 1 f in that two arms 3.4 and 3.5 are shortened and both arecoupled via a center joint 13 to two arm strips 14.1 and 14.2, which areconnected to the gripper via the joints 5 and 7. On the one hand, thisembodiment can be used to carry out the same movement process as thatdescribed with reference to FIGS. 1 a to 1 f. According to FIG. 2 b, thegripper 6 is lowered to the object 10, according to FIG. 2 c, the object10 is raised out of the container 11, according to FIG. 2 d, the object10 is transferred to a position above the supporting surface 12,according to FIG. 2 e, the object 10 is lowered onto the supportingsurface 12 and, according to FIG. 2 f, the gripping members 9 arereleased from the object 10, which remains on the supporting surface 12.

While, with the exemplary embodiment of the device according to theinvention for moving objects as shown in FIGS. 1 a to 1 f, a differentmovement of the carriages 2.1 to 12.3 admittedly allows the gripper 6 tobe tilted to a certain extent, the gripper according to the exemplaryembodiment shown in FIGS. 2 a to 2 f can be pivoted about the centerjoint 13, as shown in FIGS. 3 a to 3 f. However, in this case, it isadvisable but not necessary for at least one carriage 2.3 to be arrangedon a separate rail which, although this is not shown in any more detail,is located behind the rail 1.

According to FIG. 3 a, the carriages 2.1-2.3 are located relativelyclose to one another. In this case, the gripper 6 has been pivotedthrough more than 90°, as a result of which it can take an object 10from a stack 15 which is arranged inclined with respect to the container11. For this purpose, the two carriages 2.1 and 2.2 are moved somewhataway from one another and all three carriages are moved to the stack 15,with this movement taking place continuously thus resulting in the stack15 being approached obliquely. In consequence, the gripping members 9can also grip the object 10 obliquely, as is shown in FIG. 3 b. Thecarriages 2.1 to 2.3 are now moved back to the initial position as shownin FIG. 3 a, with the gripping members 9 holding the object 10, as shownin FIG. 3 c. The carriages 2.1 to 2.3 are then moved away from oneanother, as a result of which the gripper 6 is pivoted to the positionshown in FIG. 3 d, in which the object 10 is located above the container11.

According to FIG. 3 e, the two carriages 2.1 are now once again movedtowards one another, while the carriage 2.3 follows the carriage 2.1.This results in the gripper 6 being lowered exactly vertically, as aresult of which the object 10 can be transferred into the container 11.The carriages 2.1 to 2.3 are then once again moved back to the initialposition as shown in FIG. 3 d, but with the object 10 remaining in thecontainer 11, as shown in FIG. 3 f.

While, in the case of the exemplary embodiment shown in FIGS. 1 a to 1f, the carriages 2.1 to 2.3 can be arranged on the same rail 1, theymust be arranged on different rails when the aim is to pivot the gripperover a greater pivoting extent, in which case a second rail may belocated behind the first rail. In the exemplary embodiment shown inFIGS. 4 a to 4 f, the carriages 2.1 and 2.3 are located on the same rail1, while a dedicated rail is provided for the carriage 2.2. In thisarrangement, the gripper 6 could even be pivoted through 360° about thejoint 5.

However, in particular, an attachment 16 is also shown on the grippersurface 6 in the exemplary embodiment, with the gripping members 9 beinglocated on an obliquely positioned transfer surface 17. An attachment 16such as this also makes it possible to take an object 10 from a stack 15when this stack 15 is located at a position which otherwise cannot beaccessed by the gripper 6. This can be seen in particular in FIG. 4 a,in which the arm 3.2 is virtually vertical and the carriages 2.1 and 2.3have been moved as far away from one another as possible. Even if thetwo carriages 2.1 and 2.3 were now to be moved to the left, thusresulting in the gripper 6 being pivoted further about the joint 5, thegripping members 9, which would then have been rotated to a transferposition, will be arranged too high to allow them to approach the stack15. This is compensated for by the attachment 16. The gripping members 9approach the object 10 and remove the object 10 by appropriate controlof the movement paths of the carriages 2.1 to 2.3, as shown in FIGS. 4 band 4 c.

However, in order now to position the object 10 approximatelyhorizontally above the container 11, the gripper 6 must be pivoted inthe opposite direction about the joint 7. This is achieved in particularby the carriage 2.2 moving past the carriage 2.3, as shown in FIGS. 4 dand 4 e. The in-use position as shown in FIG. 4 f corresponds to thatshown in FIG. 4 d.

As shown in FIG. 5, the gripper 6 is connected like a parallelogram viathe two arms 3.2 and 3.3 to a common carriage 2.4, while only the onecarriage 2.1 is provided for the arm 3.1. For this purpose, however, thearm 3.1 also does not have a common articulation point on the gripper 6with one of the arms 3.2 or 3.3, and, instead, the arm 3.3 has its ownjoint 29 with the gripper 6. This joint 29 is located between the joints5 and 7. It is also feasible, although this is not shown here, for thearm 3.1 to be connected to the joint 29 and for the arm 3.3 to beconnected to the joint 7. However, this would increase the physical sizeof the overall device.

The parallelogram-like connection of the gripper 6 to just one carriage2.4 and the provision of a dedicated joint 29 admittedly stabilizes theguidance of the gripper 6, but only raising and lowering are possible,and the gripper 6 cannot be pivoted.

The exemplary embodiment shown in FIG. 6 differs from that shown in FIG.5 in that the gripper 6 is additionally connected via a force store 30to the carriage 2.4, with the force store 30 in the present exemplaryembodiment being in the form of a helical spring, and being connected tothe joint 29. This force store 30 ensures that, in the event of apossible electrical power failure, the gripper 6 will not falldownwards, but is held firmly in its position as predetermined by theforce store 30.

The exemplary embodiment shown in FIG. 7 differs from that shown in FIG.6 in that each arm 3.1 to 3.3 once again has its own respective carriage2.1 to 2.3 on the rail 1, instead of the single carriage. This providesthe capability for the gripper 6 to be pivoted about the joint 29, forexample.

As shown in FIG. 8, the device according to the invention is suitablenot only for moving objects but also for their handling or treatment. Inthis case, the objects 10.1 are located on a table 31. The Figure alsoshows that the entire device cannot just be arranged on a ceiling,working in the vertical, but, for example, it could also be provided ona wall, which is not shown in any more detail, in such a way that thearms 3.1 to 3.3 move horizontally on the carriages 2.1 and 2.4. Acorresponding tool 32 is then located on the corresponding gripper 6,which in this case is in the form of a mounting plate.

According to the present invention, the carriages are intended to bemoved with the aid of linear drives. One such drive is illustratedschematically in FIG. 9. In this exemplary embodiment, the linear drive18 is arranged on the rail 1, with the rail 1 having a cross section inthe form of a horizontal I. Permanent-magnet strips 19 of the lineardrive 18 are indicated and are located one behind the other on thesurface of the rail 1 in a row, with a corresponding pole alignment.

A row of windings 21 which can be energized is located above thesepermanent magnet strips 19, and separated by an air gap 20. This allowsa carriage housing 22, which is in the form of a box, to be movedlinearly along the rail 1, with this carriage housing 22, which is inthe form of a box, clasping the rail 1. It is supported on both sides ofthe linear drive 18 against guide rails 23.1 and 23.2, which are claspedby corresponding running rails 24.1 and 24.2.

Two holding lugs 25.1 and 25.2 are provided at the bottom on thecarriage housing 22 and a hinge bolt 26, which forms the joint 4.1,passes through them. The arm 3.1 is attached to this hinge bolt 26 and afurther hinge bolt 27 is located at the free end of this arm 3.1 andforms the joint 7. The gripper 6 is attached in an articulated mannerthereto.

1-18. (canceled)
 19. A device for handling molds for the production ofchocolate articles, comprising a gripper which is arranged on at leastthree arms which can each be moved along at least one rail on two outercarriages and one inner carriage, the at least three arms include anouter arm on the outer carriage which crosses an inner arm on the innercarriage, wherein the outer arm, which crosses the inner arm, forms acommon joint with a further outer arm on the gripper, or crosses thefurther outer arm and forms its own joint with the gripper.
 20. Thedevice as claimed in claim 19, characterized in that the two arms areconnected to two arm strips via a center joint, and the arm strips areseparately coupled to the gripper at the other end.
 21. The device asclaimed in claim 19, characterized in that an attachment with a transfersurface, which is positioned obliquely with respect to the grippersurface, is located on the gripper.
 22. The device as claimed in claim19, characterized in that the carriage has a box housing which claspsthe rail.
 23. The device as claimed in claim 19, characterized in thatthe carriage is supported on both sides alongside the linear drive onguide rails.
 24. The device as claimed in claim 19, characterized inthat permanent-magnet strips are arranged linearly, as part of a statoron the rail, and windings are arranged linearly on the carriage, withthere being an air gap between the permanent-magnet strips and thewindings.
 25. The device as claimed in claim 19, characterized in thatthe linear drive has an associated second linear drive which runsobliquely with respect to it.